This application claims the priority of Austrian Patent Application Serial No. GM 513/2000, filed Jul. 13, 2000, the subject matter of which is incorporated herein by reference.
The present invention relates, in general, to a track renewal machine.
U.S. Pat. No. 4,854,243 describes a machine for renewing a track composed of two rails fastened to ties supported on ballast. The track renewal machine includes a machine frame extending in a longitudinal direction and having opposite ends supported on the track by undercarriages. The machine frame has a front frame part and a rear frame part, arranged one following the other in the longitudinal direction, with a frame joint connecting the front and rear frame parts to one another. Drives interconnect the front and rear frame parts in an upper region thereof to spread the frame parts apart, whereby the frame parts are raised in a vertical direction at the frame joint. The machine further includes a tie lifting device and a tie laying device, mounted on the machine frame between the undercarriages and spaced from one another in the longitudinal direction; an endless ballast clearing device for taking up ballast, mounted on the machine frame between the tie lifting device and the tie laying device and designed to be set in rotation by a drive; and first conveyor, cooperating with the ballast clearing device, for transporting away taken-up ballast. After removal of the old ties, ballast from the cribs between the ties remains lying on the ballast bed, creating an obstacle for laying the new ties. This crib ballast is taken up by the ballast clearing device, having the shape of an endless chain, and is transported upwards to the conveyor. After being moved to the rear end of the machine, the ballast is discharged upon the new track which has been laid in the meantime in the intervening space. This serves to ballast the new ties resting on the newly graded ballast bed and thus to stabilize the track position.
French Pat. No. FR 2 736 367 A describes a track renewal machine which essentially includes a first machine unit for picking up the old ties, a trailing ballast cleaning unit, and a further machine unit for laying the new ties. The ballast cleaning unit includes a clearing chain which cooperates with a ballast screen in which the soiled ballast is cleaned. Located immediately behind the clearing chain in the operating direction is a ballast discharge station for returning cleaned ballast to the track, and a planing and consolidating device.
It would be desirable and advantageous to provide an improved track renewal machine which is simple in structure and can easily be modified for use for a wide range of jobs.
According to one aspect of the present invention, a track renewal machine includes a machine frame extending in a longitudinal direction and supported on the track for mobility in an operating direction, the machine frame defining a machine end with regard to the longitudinal direction; a tie lifting device, mounted on the machine frame, for picking up old ties; a ballast clearing device for taking up ballast, arranged following the tie lifting device in the operating direction and having a discharge end; a first conveyor unit, provided on the machine frame behind the ballast clearing device, for transporting ballast to the machine end; a ballast chute arranged at the machine end; a tie laying device, mounted on the machine frame, for laying new ties; a ballast planing apparatus mounted on the machine frame immediately ahead of the tie laying device in the operating direction; and a second conveyor unit mounted on the machine frame and extending in the longitudinal direction and having a receiving end positioned at the machine end and a discharge end arranged above the ballast planing apparatus.
By providing the two conveyor units on a machine for renewing a track, it becomes possible in the course of track reconstruction work to undisturbedly transport away soiled ballast and at the same time deliver cleaned ballast to the work site. As the ends of the two conveyor units are positioned at the end of the machine or machine frame, there is the advantageous possibility to couple a screening car to the machine, if required. As a result, the entire region of the track renewal gap can be used unhinderedly for exchanging ties. If the track is to be renewed without simultaneously cleaning the ballast, then the screening car can be conveniently and quickly uncoupled from the machine.